Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Intangible Liability Disclosure [Abstract]
Amortization expense	$ 0.2	$ 0.2	$ 0.3	$ 0.3